Four-time Olympic champion Ben Ainslie made a successful debut in his transition to AC45s. His J.P. Morgan BAR boat beat Team Korea, while Piranha beat Artemis Racing Red, and Luna Rossa Swordfish defeated China Team, all by 2-0 sweeps in the best-of-three format, making for a quick day of racing in moderate 15-knot winds.

“It’s about avoiding mistakes,” Swordfish skipper Paul Campbell-James said, “and when the breeze is a little lighter it’s easier to avoid those mistakes.”

There weren’t any surprises, even though Ainslie is a novice on these boats while Team Korea has been racing for a year. Ainslie had a crew made up of Oracle Team USA veterans on loan to his team.

His team came from behind in both races to beat Team Korea, skippered by another Olympic gold medalist, Nathan Outteridge, by 13 and 29 seconds.

“The racing is so fast – it’s a bit of a blur,” Ainslie said. “It’s full on for the guys. The whole way around they’re maxed out, doing maneuvers, getting sails up and down. As the helmsman, I’m the only one who has time to look around and make decisions. It happens so fast; I was amazed at that. And I was amazed how close the racing was for these boats.”

In the second race, he smartly held up Team Korea near the end of the second leg to give his crew time to get a balky gennaker up.

Like Ainslie’s boat, Piranha trailed in each of its races. In the second, Artemis Racing Red, skippered by Santiago Lange, drew two penalties for breaking rules on the pre-start.

In Thursday’s quarterfinals, Swordfish races against Artemis Racing White, and Piranha faces Oracle Team USA Spithill. On Friday, J.P. Morgan BAR races Emirates Team New Zealand, and France’s Energy Team takes on Oracle Team USA Coutts.

The quarterfinals are one-race affairs, as are the semifinals Saturday and the final Sunday. Thursday’s first fleet race begins at 2:50 p.m., the second at 3:25 p.m.

Hildebrand gets a ride: Race car driver J.R. Hildebrand, headed for Sunday’s GoPro Indy Grand Prix of Sonoma, rode on Jimmy Spithill‘s Oracle Team USA boat in a practice session. “I got a chance at the end to steer the boat and feel how quickly things change and how quickly the boat can switch direction,” the Sausalito native said.